Marine-boiler and other furnace.



R. CAMPBELL.

MARINE BOILER AND OTHER FURNACE.

APPLICATION TILED IEB. 2, 1012.

Patented Mar. 17, 1914.

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R. CAMPBELL.

MARINE BOILER AND OTHER FURNACE.

APPLICATION FILED FEB. 2, 1912.

1,090,273. Patented Mar. 17, 1914.

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R. CAMPBELL.

MARINE BOILER AND OTHER FURNACE.

APPLIOATION FILED FEB. 2, 1912.

1,090,273. Patented Mar. 17,1914.

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v removed; Fig. 3, a cross section on RICHARD CAMPBELL, OF LIVERPOOL, ENGLAND.

MARINE-BOILER AND OTHER FURNACE.

Specification of Letters Patent.

Patented Mar. 17, 1914.

Application filed February 2, 1912. Serial No. 675,046.

To all whom it may concern:

Be it known that I, Brennan CAMPBELL, subject of the King of Great Britain. residing at Liverpool, in the county of Lancaster, in the Kingdom of England, have invented certain new and useful Improvements in Marine-Boiler and other Furnaces, of which the following is a specification.

This invention has reference to fire-grates for marine boiler and other furnaces, and has for its object certain improvements which will result in the saving of fuel and cause better combustion, also the fire adjacent to the back end of the grate will be cleaner, and any accumulation of dead fuel thereat avoided.

According to the present invention, the furnace bridge is formed hollow, and is provided in front with an auxiliary sloping grid, so as to bridge over the part of the main grate which is not gridded. Incoming air has direct access to the hollow space under the sloping grid and to the hollow bridge also, and the sloping grid is prevented from getting unduly hot. Furthermore the said incoming air is heated in the hollow space and in the hollow bridge to such an extent that as it issues through the air outlet orifices in the bridge, it readily combines with the products of combustion issuing from the furnace while the air passing through the interstices in the sloping grid direct into the fire, assists in their complete combustion. A hollow fire bridge used separately is known and sloping auxiliary bars hooked on to a back bearer to form a bridge is also known, but a hollow bridge and sloping auxiliary bars have never before been used in combination.

My invention further consists in making the bridge with its auxiliary grid capable of being moved longitudinally of the main grate, so that the area of the main grate can be increased or decreased as required.

These and other improvements will he understood from the following description, reference being had to the accompanying drawings, in which,

Figure 1 is a longitudinal section of a furnace embodying my improvements, showing the fire bridge moved back into its rearmost position; Fig. 2, a sectional plan view thereof with the cover plate of the bridge the line A B of Fig. 1, one half having the sloping grid in position, and the other half with the sloping grid removed; and Fig. l, a longitudinal section of part of the furnace showing the tire bridge moved into the forward position.

In these drawings, 1 is the main grate of the furnace. 2 the front dead plate, 8 the foundation or back dead plate, 4 the furnace flue, 5 the hollow fire bridge which is seated on the foundation plate 3, and 6 a mechanical arrangement for giving motion to the tirebars, which forms no part of this invention, and may be used or not as desired. In front of this hollow bridge at the back of the main gate is the auxiliary grate 7, which slopes upward from the main grate to the top or near the top of the bridge either to an inclined plane, or in curved, bowed, or other form, and bridges over the part of the grate which is not gridded. This auxiliary grate is composed of bars, the lower ends of which are beveled off on the underside 8 so that the bevel rests on the main grate, while the upper ends have claws t) engaging the ribs or bearers 10 and 11 projecting forward from the hollow bridge, so that these bars are held in position while the trianguhir space 12 below the sloping grid forms a cavity into which air has free access through the spaces 13 between the main bars and through the openings 14.

The ribs 10 and 11 are spaced apart, the ribs 10 curving upwardly while the ribs 11 curve downwardly, and between them the claw 9 engages, so as to become coupled thereto in such manner that the bars would have to be lifted up to substantially a horizontal position, before they can be disengaged from the ribs 10 and 11. This prevents the bars 7 from getting accidentally dislodged. Projecting forwardly from the ends of the hollow bridge are the wings 15, one at each end of the row of bars 7. These steady the bars and keep them in position, so that they cannot get displaced laterally. I prefer to make this auxiliary grid of bars each composed of two, three or more bars cast together with connecting ribs, and with an air space 16 between each casting as in ordinary bars, so as to leave longitudinal air spaces or interstices 16 and 17, in and between each casting less in width than the air spaces 13 between the main bars 1, for which purpose there may be three or four air spaces in the auxiliary bars spaces 13 in the main bars 1. Consequently and then tighten the bolts up again. The no clinker or ash can fall into the chamber sloping auxiliary grid 7 moves with the hol- 12, that cannot fall through the spaces 13 low bridge, the downwardly extending arms in the main bars, and hence the said chamber 18 of the auxiliary grid 7 sliding along the is always kept clear. At the lower end of spaces 13 between the main bars 1. In this the auxiliary bars 7 are downwardly extendway any required grate area can be obtained, ing arms 18, which pass through the spaces and this will be found to be a very useful pro- 13 between the main bars preferably each vision where not only the quality of the fuel alternate space, and are provided at the botvaries, (as for instance where the coal is at tom with a ring 19 or abutment. The main one time very hot or quick burning, while at firebars 1 may be of the type to which a another time it is inferior or slow burning), rocking or shaking motion is applied to the but also where the load on the engines varies individual bars or to the whole grate for the from time to time so as to render it desirable purpose ofv clearing the grid of clinkers, to be able to produce more steam at one time ashes or the like. than another.

The shaking or rocking of the main bars The hollow bridge has slots 24 which in 1 imparts a similar shaking or rocking to conjunction with the slots 25 in the dead the auxiliary bars 7, and an upward. move plate supply it with air from the space 20 ment of the main bars 1 will move the auxilbelow the grate. The bridge can have bearer iary bars 7 upward, while a downward movestrips underneath, so as to be spaced a little ment will pull the auxiliary bars 7 down from the grate and form openings 26. Furwith them by means of the downwardly exthermore, openings 27 are provided above. tending arms 18. Furthermore, these down- Incoming air has access to the hollow space wardly extending arms 18 act as a lock to 12 under the sloping grid 7, and also to the prevent the auxiliary bars separating from hollow bridge direct, and keeps the bars 7 the main bars. This shaking of the bars 1 from getting unduly hot. Furthermore the provides an efiicient cleaning of the auxiliary said incoming air is heated in the hollow grate 7, and breaks up any clinker that may space 12 and in the hollow bridge to such have formed on the grate, while the dust, an extent, that as it issues from the outlet small ash and the like fall through the apertures 28 in the bridge, it readily comspaces into the chamber 12 below, and from bines with the products of combustion issuthence into the ashpit 20, the bars being ing from the furnace, thus assisting in their placed side by side and coupled at the top complete combustion, while the air passing to the bearers to prevent them becoming through the lnterstices 16, 17, in the sloping displaced.

bars direct into the fire, assists in securing The back dead plate 3 extends the full complete combustion. Surplus air in the width of the furnace, as does also the main space 12 passes through the apertures 26, 27, grate 1, but I propose to stop off the bridge into the bridge, or if the bridge be moved 5 and the bars 7 short of the furnace sides,

into such a forward position (as shown in so as to leave a passage 21 between the ends Fig. 4) that no air can get access to the of the bridge and the furnace walls a, bridge direct through the slots 24; and 25, through which passage the flames and furthen such air obtains access through the nace gases pass, and are thereby concentrated apertures 26, 27. On the other hand if the against the furnace walls. The bearers 10, bridge be moved into such a position that 11, have openings 22, so that flue dust or ash will not lodge in them, but will escape therethrough, and these openings provide a pas sage for air to keep the bars cool.

In order to enable the grate area to be increased or decreased as required, I make the hollow bridge 5 capable of being moved longitudinally of the grate. This is effected by the hollow bridge being seated on the back dead plate 3, which dead plate forms a continuation of the grate 1, and supports the latter at the rear end by means of the bearers 23. Means are provided for bolting the hollow bridge to the back dead plate, sucl means consisting c. g. of bolts (not shown) passing throu h slots 30 in the bottom of the hollow bridge and through holes in the dead 7 to every two I move it rearward to increase the grate area,

the space 12, then surplus air passes from the bridge into the space 12 through the said apertures, and so the said space and the hollow bridge are equally supplied with air. The arrangement permits the bridge 5 to be in communication with the air supply, whatever position the bridge may be shifted into. The back end of the ash space 20 is closed by the bearer plate 29, a manhole door 39 being however provided therein. If desired the opening 27 may be closed by a stopper consisting of any convenient form of-plug.

In the embodiment shown, the bridge is tion plate 3, in which base piece are formed the slots 30 for the bolts, as well as the air plate. When the grid is cool, men can enter passages 24 already described. The base the furnace, slacken the bolts, and shift the piece has the upstanding wall 5 from the bridge forward to decrease the grate area, or front of whlch PIOJGCt the bearers or ribs 10,

more air can get into the bridge than into formed of a base piece seated on the foundatire-bridge and main grate; and means upon 11, and the wings l5 hereinbefore referred back thereof having a laterally disposed into. From the rear of this wall pro ect the ternal space; an auxiliary grate in front of said bridge inclosiug a space with the tirebridge and the main grate; and means for causing said auxiliary grate to reek in synchronism with the main grate. V

7. .111 a furnace, the combination of a line; a main grate therein; a tire-bridge at the back thereof having a laterally disposed internal space; and an auxiliary grate comprising a plurality of bars resting. on said main grate and leaning against said bridge, the apertures in the auxiliary grate being closer together than those in the main grate.

8. In a furnace, the combination of a flue: a main grate therein, a fire-bridge rearward of said main grate; side wings projecting vertically from said bridge; and a plurality of sloping grate bars between said wings and having their upper ends ren'iovably secured on said bridge and their lower ends resting on said main grate.

9. In a furnace, the combination of a flue; a main grate therein; a fire-bridge rearward of said main grate; side wings projecting vertically from said bridge; and a plurality of sloping grate bars between said wings and having their upper ends removably secured on said bridge and their lower ends resting on said. main grate and releasably locked thereto.

10. In a furnace,

wings 31, which form strengthening webs, and between each pair of wings I place a sloping plate the upper end of which hooks on to the rear face of the wall 5, while the lower end rests upon the base piece. Hence a hollow fire bridge is formed which can easily be taken to pieces. A convenient way of securing each sloping plate to the bridge wall 5, is to provide the upper end of the said plate 5* with a claw engaging ribs or bearers 33 and 3d projecting rearward from the bridge wall, so that by engaging the claw of these sloping plates between the ribs, the said plates are held in position, with a triangular space below to form a cavity into which air has free ac cess. The advantage of this arrangement is, that the bridge can readily be taken to pieces for cleaning, and re'erected in the shortest possible time.

I declare that what I claim is 1. In a furnace, the combination of a fine; a main grate therein; a longitudinally movable fire-bridge at the back thereof hav ing a laterally disposed internal space; and an auxiliary grate in front of said bridge, said auxiliary grate together with the main grate and the bridge wall inclosing a space in front of said wall.

2. In a furnace, the the combination of a flue; a main grate therein; a tire-bridge rearward of said main grate; side wings projecting vertically from said bridge; and a plurality of sloping grate bars between said wings, having their upper ends removably secured on said bridge and their lower ends resting on said main grate and having downwardly extending arms passing between the bars of the main grate.

11. In a furnace, the combination of a flue; a main grate therein; a lire-bridge rearward of said main grate; side wings projecting vertically from said bridge; a plurality of sloping grate bars between said wings and having their upper ends removably secured on said bridge and their lower ends resting on said main grate; downwardly extending arms on said sloping grate bars and passing between the bars of the main grate; and means for locking said downwardly extending arms to the main grate.

12. In a furnace, the combination of a flue; a main grate therein; a tire-bridge rearward of said main grate; side wings projecting vertically from said bridge; a plurality of sloping grate bars between said wings and having their upper ends removably secured on said bridge and their lower ends resting on said main grate; downwardly extending arms on said sloping grate bars passing between the bars of the main grate; and locking members on said dowir combination of a flue; a main grate therein; a longitudinally movable tire-bridge at the back thereof having a laterally disposed internal space; an auxil iary grate in front of said bridge which together with the main grate and the bridge wall incloses a space; and means for fixing said bridge in any desired position.

3. In a furnace, the combination of a flue; a main grate therein, a fire-bridge at the back thereof having a laterally disposed internal space; an auxiliary grate in front of said bridge forming the space in front of said bridge; and means for displacing said auxiliary grate relatively to said main grate to vary the effective grate area.

In a furnace, the combination of a flue; a main grate therein; a longitudinally movable tire-bridge at the back thereof and having a laterally disposed internal space; and an auxiliary grate in front of said bridge, movable therewith and inclosing a space with the lire-bridge and main grate.

In a furnace, the combination of a flue; a main grate therein; a longitudinally movable tire-linridge at the back thereof, having a laterally disposed internal space and an auxiliary grate in front of said bridge, movable therewith, and inclosing a space with the said. main grate for guiding said auxiliary grate. 6. In a furnace, the combination of a flue; a main grate therein; a fire-bridge at the Wardly extending arms below said main In Witness whereof, I have hereunto grate. signed my name this 20 day of J an. 1912, in 18. In a furnace, the combination of a the presence of two subscribing Witnesses. fine; a perforated foundation plate therein; R. CAMPBELL. 5 and a hollow fire-bridge slidably mounted /Vitnesses:

on said plate and having its base perforated G. C. DYMOND, to coact with the perforations in said plate. 0. BARTLETT.

Copies of this patent may be obtained for five cents each, by addressing the fiommissioner of Patents,

Washington, D. C. 

